My experience is a fraction of yours of course but I have found:
Blood knot for leaders: will never slip if the material diameter is not drastically different.
I've had surgeons knots fail on me, tha last was in a huge pod f fish when Bob P had to use one of my rods after an untimely death of his. That knot failure, the look on his face and the ensuing BS convinced me to go back to taking my time & tying a blood knot.
Palomar at the fly: 100% - never lost a fish to that know.
Hope to see you soon.